Review 13844

C. Thomas Tyler
Normalized P4INSTANCE to SDP_INSTANCE to get Unix/Windows
implementations in sync.

Reasons:
1. Things that interact with SDP in both Unix and Windows
environments shoudn't have to account for this obscure
SDP difference between Unix and Windows.  (I came across
this doing CBD work).

2. The Windows and Unix scripts have different variable
names for defining the same concept, the SDP instance.
Unix uses P4INSTANCE, while Windows uses SDP_INSTANCE.

3. This instance tag, a data set identifier, is an SDP concept.
I prefer the SDP_INSTANCE name over P4INSTANCE, so I prpose
to normalize to SDP_INSTANCE.

4. The P4INSTANCE name makes it look like a setting that might be
recognized by the p4d itself, which it is not.  (There are other
such things such as P4SERVER that could perhaps be renamed as
a separate task; but I'm not sure we want to totally disallow
the P4 prefix for variable names. It looks too right to be wrong
in same cases, like P4BIN and P4DBIN.  That's a discussion for
another day, outside the scope of this task).

Meanwhile:
* Fixed a bug in the Windows 2013.3 upgrade script that
was referencing undefined P4INSTANCE, as the Windows
environment defined only SDP_INSTANCE.

* Had P4INSTANCE been removed completely, this change would
likely cause trouble for users doing updates for existing
SDP installations.  So, though it involves slight technical debt,
I opted to keep a redundant definition of P4INSTANCE
in p4_vars.template, with comments indicating SDP_INSTANCE should be
used in favor of P4INSTANCE, with a warning that P4INSTANCE
may go away in a future release.  This should avoid unnecessary
upgrade pain.

* In mkdirs.sh, the varialbe name was INSTANCE rather than
SDP_INSTANCE.  I changed that as well.  That required manual
change rather than sub/replace to avoid corrupting other similar
varialbe names (e.g.  MASTERINSTANCE).

As this big change affects many files and is not urgent, I am
shelving it for pre-commit code review.  It is a trivial
change technically (a substitute/replace, plus tweaks in
p4_vars.template), but impacts many files.
#2: Change 13906 committed into //guest/perforce_software/sdp/dev 57 0 0
Tip: Use n and p to cycle through the changes.